An investigation into child pornography at a Prince George’s County school broadened Wednesday as officials interviewed more than two dozen families, placed the principal on leave and examined whether any policies on reporting child abuse were breached.

But officials offered few new details about how an unpaid library volunteer in suburban Maryland allegedly managed to make videos of children performing sex acts on school grounds during school hours.

Police said they have now identified 11 victims and expect that there may be more as the investigation continues.

Deonte Carraway, 22, of Glenarden has been charged with 10 counts of felony child pornography and related charges. He has admitted creating the videos, in which he sometimes can be seen or heard directing children between 9 and 13 years old to perform various sexual acts, police said.

Prince George’s County Executive Rushern L. Baker III speaks at a news conference with county education and law enforcement officials. (Mark Gail for The Washington Post)

Kevin Maxwell, the school system’s chief executive officer, said at a news conference Wednesday evening that the principal, Michelle Williams, was removed and put on paid leave out of an “abundance of caution” as the investigation at Judge Sylvania W. Woods Elementary School in Glenarden unfolds.

The move came just days after the arrest of Carraway, who allegedly produced 40 pornographic videos.

Parents are demanding to know how the abuse could have happened and how it could have gone on so long without someone noticing.

Maxwell and other county officials said Wednesday that they aren’t able to answer those questions yet.

“When we have the answer, we will be as transparent as we can,” Maxwell said.

Police said that so far, the investigation has found that Carraway directly abused seven of the 11 victims and otherwise abused the rest through his actions, without being more specific.

School system officials require background checks for volunteers, but they have not responded to questions about whether there are rules that spell out how volunteers should be supervised or whether adults are allowed to be alone with children.

Deonte Carraway (Prince George’s County Police Department)

They also haven’t answered questions about whether any school staff members were aware of suspicious behavior by Carraway before the uncle of a Sylvania Woods student found a nude photo on the child’s cellphone and reported it to police last week.

Long before news broke about the Carraway investigation, the Prince George’s state’s attorney’s office had offered to work with the school system to train staff on how to identify and report child predators.

That offer has not yet been accepted, said Angela Alsobrooks, the county’s top prosecutor, but she said Wednesday that “it is still on the table.”

Alsobrooks said school staff members “absolutely” could be charged if they are found to have failed to report suspicions about Carraway. “We will go as far as our investigation leads us, and we will take action based on what we learn,” the prosecutor said.

School and county officials said they are providing counseling services and other resources to victims and their families and are reminding school staff workers across the district of their duty under Maryland law to report suspicions of child abuse. They have also set up a hotline that anyone can use to report such suspicions.

“Every child in this county is our baby. And it is our job — it is my job — to protect them from predators like the one we arrested,” County Executive Rushern L. Baker III (D) said.

“I want you to know that we’re going to do everything in our power to make sure that this type of situation doesn’t happen again,” he added.

Some of the video recording and sex abuse took place during the school day at Sylvania Woods Elementary, where Carraway worked as a paid classroom assistant before becoming a volunteer, according to Prince George’s police.

In at least one instance, a student was recorded performing a sex act on Carraway in a school restroom while Carraway recorded it on his orange phone, according to charging documents.

On Wednesday morning, a man at the address listed for Carraway in online records declined to answer questions from a Washington Post reporter. Carraway is being held on $1 million bond.

About 700 students attend Sylvania Woods, almost all of them black and Latino. The vast majority qualify for free or reduced-price lunch, a measure of poverty.

Attempts to reach Williams, the principal, for comment were unsuccessful Wednesday.

Williams reported concerns about Carraway to police and Child Protective Services immediately after becoming aware of them, said Doris Reed, executive director of the Association of Supervisory and Administrative School Personnel, the union for those workers. CPS told the principal that police would handle it, Reed said.

“It’s a horrible situation,” Reed said. “I don’t think anyone can question that, but I hope the administration will not overreact when dealing with the principal.”

Maxwell said that the school system learned of Carraway’s arrest Saturday but did not notify parents until Monday because administrators were still gathering information.

On Wednesday afternoon, attorneys for the family of the 9-year-old victim who brought the case to police filed a civil rights lawsuit in Prince George’s County Court against the school system and Carraway.

The lawsuit says Carraway recorded students performing sex acts in the school auditorium, bathrooms and elsewhere on school property, using his position as a teacher’s assistant to remove students from class and escort them to various locations.

“Carraway told some of the students, including the Plaintiff, that they would be participating in a ‘club’ with him to help persuade them to engage in these sexual acts on camera,” the lawsuit states.

The child’s uncle found a nude photo on his nephew’s phone, sent via the anonymous messaging app Kik, according to the complaint. The uncle periodically checks the child’s phone as “an adult being vigilant,” said Dave Simpson, an attorney representing the family of the young victim.

The civil case also names Maxwell and Williams. Maxwell said he could not comment because the school system had not yet been served with the complaint.

The Prince George’s school system requires volunteers to undergo one of two kinds of background checks, according to the school system’s website. All employees and volunteers who are likely to have unsupervised contact with children are required to be fingerprinted.

Volunteers who work with children only occasionally or who work with them regularly but in supervised settings, such as a classroom, are required to get a less-intensive background check — a search of court records based on written information that the volunteer provides.

Carraway worked for the school system from 2014 until he was laid off for budgetary reasons in September 2015. As a paid employee, he worked as a classroom assistant, said schools spokeswoman Sherrie Johnson. Johnson said that at the time of Carraway’s hiring, a criminal background check was done, as happens with all employees. “It came up with nothing, no criminal history or anything,” she said.

Experts say background checks should be regarded as one part of a comprehensive plan to prevent offenders from gaining access to children at school.

Most child sex offenders don’t have a criminal history and would not be flagged by a background check, said Jennifer Alvaro, a longtime clinician in the field of child sexual abuse who has advocated for safeguards in Montgomery County schools.

Juriese Colon, executive director of outreach for the National Center for Missing and Exploited Children, said that many schools and after-school programs prohibit adults from being alone with children one-on-one; under such a policy, there must be at least two adults present as a “check and balance,” Colon said.

Carraway also made video recordings at Glenarden Municipal Center and the Theresa Banks Memorial Aquatic Center as well as in private homes, according to police.

The Prince George’s division of the Maryland-National Capital Park Police has jurisdiction over the aquatic center.

Acting Chief Stanley Johnson said Carraway, as a Glenarden resident, would have had access to the aquatic center with an activity card that all local residents are required to use to enter.

The last time the agency recorded Carraway entering the pool with an identification card was in 2014. It has no record of him entering the facility since then, but “there is a possibility that someone can be part of a program or special event and might gain access,” Johnson added.

If Carraway was working with the school system, Johnson said, he could have had access to the facility through a swim program it offers as part of a partnership with the county parks department.

Hamil R. Harris and Arelis R. Hernández contributed to this report. Investigators ask anyone with information about this case to call 800-CALL-FBI or 301-772-4930.